During the operation of modern internal combustion engines, in particular in the case of internal combustion engines with two rows of cylinders, disturbing exhaust-gas noises commonly arise in the exhaust tract depending on the configuration and arrangement of silencer devices. DE 197 43 446 A1, which is incorporated by reference herein, discloses an exhaust system for an internal combustion engine, in which a silencer is designed as a Helmholtz resonator. A closable exhaust-gas flap is provided at said silencer. By virtue of said exhaust-gas flap being closed, an escape of the exhaust-gas flow from said silencer is prevented. Said silencer thus acts as a Helmholtz resonator.
DE 102 31 056 A1, which is incorporated by reference herein, describes an exhaust system which has two silencer devices through which flow can pass in parallel. The silencer devices are designed differently with regard to silencing action and throughflow resistance. Here, depending on the load point of the internal combustion engine, the entire exhaust-gas flow is diverted into one or the other silencer device by means of a switching device.
Furthermore, DE 10 2006 020 155 A1, which is incorporated by reference herein, discloses an exhaust system for an internal combustion engine, in which, in a tailpipe of an exhaust tract, there is arranged an exhaust-gas flap which is closed or opened as a function of the engine rotational speed.